Gas turbine engines typically include a compressor section or zone, a combustor section or zone, and a turbine section or zone. A compressor located in the compressor zone compresses air. This compressed air is mixed with fuel and channeled to the combustor zone. The air-fuel mixture is then ignited in a combustor or combustor can to generate hot combustion gases. These combustion gases expand and are channeled to the turbine zone to rotate the turbine. The rotation of the turbine generates mechanical energy that may be used to perform useful work such as, for example, powering an electrical generator or propelling an aircraft in flight.
Gas turbine engines are very versatile and may be pressed into operation in a wide variety of operating conditions. Because operating conditions may widely vary and may be unpredictable, it is desirable that the process of combustion in a gas turbine engine remains consistent and stable during operation. Instability in the combustion process may lead to undesirable results in a gas turbine engine, such as component failure and inefficient power generation. A stable combustion process typically reduces engine blowout while achieving expected thrust or power levels for the gas turbine engine. When a gas turbine engine is operated using dry low nitrous oxide techniques, combustion stability facilitates controlling nitrous oxide and carbon monoxide emissions. Because a stable combustion process is important to the efficient operation of a gas turbine engine, monitoring combustion stability during operation of a gas turbine engine is desirable.